Until the late 1940's and early 1950's, virtually all automotive vehicles were provided with manually controlled transmissions. In the late 1940's and early 1950's, automatic transmissions were brought forth which utilize hydraulic logic controlled clutches and synchronizers along with a torque convertor to automatically make the gearing shifts needed when operating the vehicle. In the 1980's, many automotive transmissions were converted to being electronically controlled rather relying upon hydraulic logic controlled valves to operate the transmission to thereby provide more optimum shift points to increase vehicle mileage. With the utilization of electronic control, much of the hydraulic mechanisms controlling the transmission are operated by solenoid actuated valves. The solenoid actuated valves typically control a spool valve mounted within a valve body. The spool valve is manipulated in many applications to connect a control pressure (a port connected with a clutch or synchronizer) with a supply pressure (a port connected with a pump) or with an exhaust pressure (a port connected with a sump). Many of the solenoid valves utilized in a transmission are mounted within a common valve body. The valve body is typically a multi-passage member providing passages to and from the hydraulic supply, control and exhaust ports of a number of spool valves and solenoid valves for the control of various clutches, synchronizers or other hydraulic functions of the transmission.
Referring to FIGS. 1, 2 and 3 a prior art valve arrangement 17 is shown. In the prior art valve arrangement 17, there is a spool valve 19 with metering cylindrical block valve head lands 27 and 14 operating within a first portion 41 of a valve body. The valve lands 27 and 14 are joined by a valve groove or stem 13 The valve body first portion 41 has a generally cylindrical hole 43 that provides a metering orifice between a first supply port opening 23 and a second control port opening 21. To connect a first supply port opening 23 with a second control port opening 21, the spool valve 19 is moved in a direction that the metering land 27 passes out of the cylindrical hole 43 and thereby enters the second control port opening 21, allowing hydraulic communication from said first supply port opening 23 to said second control port. Fluid initially enters the second control port opening 21 at two shaped control edges 39 oriented 180 degrees from each other. As the metering land 27 enters further into the second control port opening 21, eventually, fluid may enter along the full 360 degree perimeter of the metering land 27. Fluid flowing into the second control port opening 21, exits the control port at an outlet end 35 of the second control port opening 21. In the port opening geometry of prior art, the fluid metering 180 degrees opposite of the outlet end 35 (towards the semi-circular blind end 31) must flow all the way around the valve while fluid metering directly in front of the outlet end 35 has an unimpeded exit flow. The result is that at high metering flows, pressure can build up 180 degrees from the outlet end 35 creating and unbalance pressure profile around the valve. Although functionally the above noted design is sufficient, the pressure imbalances can impart lateral forces on the spool valve 19 which may lead to excessive friction and wear between the spool valve 19 and valve body first position 41. It is desirable to provide a valve arrangement wherein these lateral induced forces are minimized and therefore reduce or eliminate any laterally induced force wear upon the valving arrangement.